Date

Evidence of the Cabibbo Suppressed Decay $\Lambda_c^+ \to p K^- K^+$

The E687 collaboration Frabetti, P.L. ; Cheung, H.W.K. ; Cumalat, John P. ; et al.
Phys.Lett.B 314 (1993) 477-481, 1993.
Inspire Record 356600 DOI 10.17182/hepdata.42675

We report evidence for the Cabibbo-suppressed decay of the charm baryon Λ c + into the final state pK − K + . The analysis is performed on data collected by high energy photoproduction experiment E687 during the 1990–1991 Fermilab fixed target run. The branching ratio of the decay Λ c + → pK − K + relative to the non-suppressed Λ c + → pK − π + is measured to be BR( pK − K + / pK − π + ) = 0.096 ± 0.029 ± 0.010. The upper limit of the decay into pø relative to the inclusive pK − K + decay is measured to be BR( pø / pK − K + < 58% at the 90% confidence level.

2 data tables

Branching ratio of Cabibbo-suppressed and resolved modes.

No description provided.


Production and decay of the D(s1)+ (2536)

The CLEO collaboration Alexander, James P. ; Bebek, C. ; Berkelman, Karl ; et al.
Phys.Lett.B 303 (1993) 377-384, 1993.
Inspire Record 352823 DOI 10.17182/hepdata.47264

Using the CLEO-II detector at CESR, we have observed the D s 1 (2536) + in the decay modes D s1 + →D ∗0 K + and D ∗+ K S + , and measured its fragmentation and production ratios. Using the helicity angle distribution of the daugter D ∗0 , we obtain new evidence for the assignment of 1 + for the spin and parity of the D s 1 + . We also set upper limits on the decays D s1 + →D s ∗+ λ, D 0 K + and D + K s 0 .

2 data tables

No description provided.

No description provided.


Cross-sections of backward proton production in 40-GeV/c pi- (K-, anti-p) A interactions

Antipov, Yu.M. ; Batarin, V.A. ; Bezzubov, V.A. ; et al.
Nucl.Phys.A 536 (1992) 637-647, 1992.
Inspire Record 337176 DOI 10.17182/hepdata.36704

The inclusive cross sections of backward proton production in π − ( K − , p ) -Be, Al, Cu, Pb interactions at 40 GeV/ c are presented. Protons have been detected in the angular range 150°–165° and kinetic energy region 0.1–0.3 GeV. The invariant cross-section ratios for various beam particles are independent of the values of kinetic energy and of the nuclear target type: 〈ƒ K − /ƒ π − 〉= 0.87 ± 0.03 stat ± 0.03 syst , 〈ƒ p /ƒ π − 〉 = 1.82 ± 0.10 stat ± 0.05 syst . The A -dependence of the cross-section slope parameter for A ⩾27 is less than ∼2%.

22 data tables

CYCLE N1.

CYCLE N1.

CYCLE N1.

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Test of {QED} in $e^+ e^-$ Annihilation at Energies Between 12-{GeV} and 31.6-{GeV}

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 94 (1980) 259-265, 1980.
Inspire Record 153127 DOI 10.17182/hepdata.45228

We have measured the reactions e + e − → e + e − → μ + μ − and e + e − → γγ at c.m. energies between 12 and 31.6 GeV. Excellent agreement with the predictions of QED has been found, resulting in cut off parameters Λ + > 112 GeV and Λ − > 139 GeV for the first process and Λ + > 34 GeV and Λ − > 42 GeV (95% c.1.) for the last one. A limit on the Weinberg angle of sin 2 θ W < 0.55 (95% c.1.) has been obtained.

3 data tables

SIG(C=QED) QED predictions for the cross sections. Only statistical errors are given.

SIG(C=QED) QED predictions for the cross sections. Only statistical errors are given.

SIG(C=QED) QED predictions for the cross sections. Only statistical errors are given.


Confirmation of the Existence of the $\Sigma_c$ $^{++}$ and $\Lambda_c$ $^+$ Charmed Baryons

Baltay, C. ; Caroumbalis, D. ; French, H. ; et al.
Phys.Rev.Lett. 42 (1979) 1721, 1979.
Inspire Record 140761 DOI 10.17182/hepdata.50280

In a broadband neutrino exposure of the Fermilab 15-ft bubble chamber, we observe the production of the Σc++(2426) charmed baryon followed by its decay to Λc+(2260) and π+. We find the mass of the Λc+ to be 2257±10 MeV and the m(Σc++)−m(Λc+) mass difference to be 168±3 MeV. Previously unseen two-body decay modes of the Λc+(2260) are observed.

1 data table

No description provided.


Experimental Limits on Heavy Lepton Production by Neutrinos

Cnops, A.M. ; Connolly, P.L. ; Kahn, S.A. ; et al.
Phys.Rev.Lett. 40 (1978) 144-146, 1978.
Inspire Record 121918 DOI 10.17182/hepdata.37905

We present upper limits on the production of heavy leptons (L±) by neutrinos via the process νμ+Ne→L±+⋯, L±→e±+ν+ν¯. These limits imply that the L− and L+, if they couple in full strength to νμ, are heavier than 7.5 and 9 GeV, respectively. They also imply that the coupling strength νμ to the recently discovered 1.9-GeV heavy lepton τ is less than 0.025 of the normal νμ−μ coupling.

1 data table

No description provided.